Lesson I didn't learn shows up as learned

[BlackCatAoife]

I have started to learn French and just passed the first checkpoint. Now it tells me that I also already completed the first Être / Avoir-lesson...which I didn't.
I started French from scratch and took no test at the beginning so it can't have been that I somehow managed that skill in the tests but failed the more basic ones.

Is that a bug? Or is there a reason for this?

[Yerrick]

I believe the learned flag may be based purely on vocabulary. If a later lesson adds no new words to the list of vocabulary you have already learned, and you've been reviewing extensively, you may encounter this.

[BlackCatAoife]

Thanks! That would explain it. I had wondered if it might have been because it already came up earlier in the lessons but though that in this case there would be no need for the lesson at all.
But that way it makes sense (I'm still very motivated and keep all my strength-bars full)